Treatment of textiles



United States Patent 2,940,863 TREATMENT 0F TEXTILES Alan Bennett, Stalybridge, and Derek Wallwork Heywood, Pendlehury, Manchester, England, assignors to British Industrial Plastics Limited, London, England, a corporation of England No Drawing. Filed Dec. 15, 1958, Ser. No. 780,239- Claims priority, application Great Britain Dec. 18, 1957 26 Claims. (Cl. 117-11) This invention relates to the treatment of fibrous materials so as to deposit hydrophilic colloids therein for filling, stitfening, bonding and like purposes.

In the case of textiles, with which the invention is especially concerned, the treatment is generally described as finishing, which includes not only filling, stiffening or bonding but also imparting a surface glaze or delustering or" filaments, or producing embossed and like mechanical effects. The treatment may also be applied to webs of fibres such as are known as non-woven fabrics, in which case the hydrophilic colloid may serve the primary purpose of bonding the fibres together, particularly at their points of intersection.

The fibres concerned are generally cellulosic such as cotton and viscose, or cellulose derivatives such as cellulose acetate, but there is no particular limitation as to this. They may be made from various synthetic substances.

Proposals have been made heretofore for enhancing the fixation of the deposited colloid in the textile or other form of fibrous material, and especially 'for improving the resistance of the colloid to removal when the fibrous material is subsequently subjected to aqueous treatments, e.g. washing.

It is already known to use starch as a stiffening agent for textile fabrics, but the use of starch alone has the disadvantage that the stiflening eliect is not wash-fast. This difliculty has been overcome by combining the starch treatment with a resin treatment so as to increase the wash-fastness of the stifiening eliect. Thus, for example, a urea-formaldehyde condensation product and a catalyst therefor have been included in an aqueous preparation of the starch used for impregnating the fabric. The use of the resin, however, has generally required severe heat treatment of the nature of a baking treatment, carried out in equipment additional to that employed for impregnation and drying.

The object of the present invention is to obviate such severe heat treatment.

According to the invention, a process of deposition of hydrophilic colloids in fibrous materials for filling, stiffening, bonding or other useful purposes, in which process a fibrous material is impregnated with an aqueous preparation containing the colloid, a urea-formaldehyde condensation product and a catalyst for the latter, is characterised in that in the making up of the aqueous preparation there is used a urea-formaldehyde condensation product of a degree of condensation in which it has a low water tolerance (i.e. can be dissolved in strong solution but not in weak solution), and that an aqueous solution of such condensation product is diluted with water in the presence of the colloid so that it is thrown out of solution into intimate association with the colloid.

The mol ratio of urea to formaldehyde in the condensation product may be between 1:15 and 1:2, preferably between 1:1.6 and 1:1.8.

The degree of condensation of the urea-formaldehyde condensation product is such, as hereinbefore stated, that it can be dissolved in strong but not in weak aqueous solution. Usually the solid content of the strong solu- 2,940,863 C6 Patented June 14, 1960 tion would not be higher than about because if it were higher the solution would be difiicult to pour. As to the minimum extent of dilution required for the condensation product to be thrown out of solution, this may vary over a fairly wide range subject to it being borne in mind that it is essential according to the invention that the degree of condensation of the condensation product should be sufiiciently advanced for eventual curing to be effected without resort to baking. For practical purposes the minimum extent of dilution required, at 15 0., should be within a range corresponding at one end of the range to a solid resin content of 40% in the aqueous preparation and at the other end of the range to a solid resin content of 10% in the aqueous preparation. In other words the degree of condensation may be so advanced that the resin hydrophobes when diluted to about 40% solids or rather less advanced so that the resin does not hydrophobe until diluted to about 10% solids, based in each case on the temperature being at 15 C.

For most treatments the amount of resin in the aqueous preparation would not exceed about 10% but in some cases, e.g. where a very stifi fabric is required, the amount may be as much as 30% or so.

The catalyst is preferably'tartaric acid, but may be another acid, or a substance having an acid reaction or developing an acid reaction in presence of formaldehyde, e.g. ammonium salts.

Various hydrophilic colloids may be used, eg starch, gelatine, carboxymethyl cellulose, polyvinyl acetate and polyvinyl alcohol. Starch is generally very useful and it has a particular advantage when applied to viscose or other lustrous fibres since it imparts a delustering effect.

As regards the relative proportions of resin and colloid, it should be understood that if the proportion of resin is too low the finishing effect on the fibrous material will be insufilciently resistant to washing or other aqueous treatments, whilst if the proportion of colloid is too low the aqueous preparation for the treatment of the fibrous material may be insufiiciently stable. Normally the ratio of resin to colloid would be within the range of 1:4 and 4:1, preferably 1:2 and 2:1, but in the case of highly viscous colloids the ratio of resin to colloid may be as high as 15:1.

The process of the invention is most conveniently carried out by padding the fabric or other form of fibrous material in a previouslyprepared dilute aqueous preparation, and then drying, for instance on heated drying cylinders.

The following examples are given for the purpose of illustrating the invention; all parts are by weight.

Example 1 70 parts of maize starch were made into a slurry with a small amount of cold water, then further water was added to make a dilute starch colloidal suspension which was heated until the starch suspension clarified.

A urea/formaldehyde resin solution of about 80% solids content, and containing urea/formaldehyde in a molecular ratio of l/ 1.7, was made up, the resin being of such a degree of condensation that it would settle out of solution overnight if diluted with twice its weight of water at 15 C. 0.5 part of tartaric acid catalyst were added to 70 parts of this resin .solution, and the resulting catalyst/resin aqueous mixture was stirred into the starch colloidal suspension, making up a dilute aqueous mixture of the following composition:

70 parts-resin solution (80% solids content) 70' partsmaize starch powder 0.5 paw-tartaric acid Balance to make up 1,000 partswater Cotton and viscose fabrics were padded n this mix- The following dilute aqueous mixture was made up 7 using the procedure described in Example 1:

I Example 3 The following diluteaqueous mixture Was made up using the procedure dscribedin Example 1: 60 partsthe above-mentioned resin solution 60 parts-maize starch powder 0.3 park-tartaric acid Balance to make up to 1,000 p arts-water A fabric formed from bright filament viscose rayon was padded in the above-mentioned mixture and dried on cylinders at 100 C. to give a stifiened wash fast fabric as before, and in addition the bright filament viscose was dclustered by the treatment. a

Example 4 The procedure described'in' Example .3 was carried out, except that the resin/starch mixture contained 1.2 parts of monoammonium phosphate instead of. 0.3 part of tartaric acid, A satisfactory, wash-fast stiffening efiect, combined with a delustering treatment ,was imparted to the, fabric, as in Example 3. I I Example 5 50 parts of gelatine powder were made into a slurry with cold water, and then hot water-at 50-60" C. was added. parts of methanol was added, and then 40, parts of the'abovementioned resin solution were added (80% solids content) and 0.25 parts of tartaric acid with stirring.

The dilute aqueous ing composition:

50 partsgelatine powder 10 parts-methanol 40 parts-the above-mentioned resin solution (80% solids content) 0.25 parts-tartaric acid Balancevto make up to-l,000 parts-water A fabric formed from bright spun viscose was padded in this dilute aqueous mixture, and dried at 100 C. on drying cylinders to give a non-delustered fabric having a stiffened finish of satisfa'ctory wash-fastness.

Example 6 V r The following dilute aqueous mixture was made up by first slurrying the colloid, and then adding theresin/catalyst' solution: 20 partssodium carboxymethyl cellulose V t 40 partsthe above-mentioned resin solution (80% solids content) 7 r 0.2 parttartaric acid Balance to make up to 1000 parts-avater w w A fabric formed from bright; filament. viscose rayon was padded inthis dilute'a queousr mixture, and dried at 100 C. on drying cylinders to give a non-matt durable stifiened finish.

A further fabric composed of cotton fibres was padded through the dilute aqueous mixture, and similarly dried mixture obtained had the follow;

on drying cylinders to give a stiffened finish of satisfactory wash fastness. v l- 7 Instead of merely dryingthe impregnated fabrics on drying cylinders, the fabrics may be passed between heated embossing rollers or glazing bow1s, so as to impart a mechanical effect to the fabric.

The following examples give compositions of aqueous preparations suitable for the impregnation of fibrous webs in the manufacture of non-woven fabrics. After impregnation the webs are dried at temperatures of 100- 110 0, thus producing a fabric in which the fibres are bonded together at their'intersecting points, the bond being resistant to waterI The resin solution mentioned in the following examples is the same as described in Example 1. V

' Example 7 Resin solution 40 Starch I 20 Tartaric 0.2 Water, to make up to 1000 parts. Example 8 t Parts Resin solution Sodium carboxymethyl cellulose 10-30 Ammonium chloride 0.1-0.2 Water, to make up to 1000 parts.

' Example 9 r r Parts Resin solution j 20-40 Polyvinyl alcohol 30 Tartaric acid 0.1-0.2

Water, to make up 'to' 1000 parts.

What is claimed is: T

- brous materials, in which process a fibrous material is impregnated with an aqueous preparation containing the colloid, a urea-formaldehyde condensation product, and a catalyst for the latter, a urea-formaldehyde condensation productofI low water tolerance being used in the making up of the aqueous preparation, an aqueous solution of said condensation product being diluted with water in the presence of the colloid so that it is thrown out of solutioninto intimate association with the colloid, the aqueous preparation containing up to 30% of the .condensation product.

2. Process of claim 1 in which the hydrophilic colloid is a substance selectedfrom the group consisting of starch, gelatine, carboxymethyl cellulose and polyvinyl alcohol.

. 3. Process of claim 1 applied to woverrfabrics of cellulose.

4. Process of claim 1 applied to woven fabrics of regenerated cellulose. H 1

5. Process of claim 1 applied to non-woven fibrous fabrics. r

6. Process of claim 1 in which the mol ratio of urea to formaldehyde in the condensation product is between 1:1.5 and 1:2. v

7. Process of claim 1 in which the mol ratio of urea to formaldehyde in the condensation product is between 121.6 and 1:1.8. 7

8. Process of claim 1 in which the degree of condensation of the condensation product is such that it will hydrophobe as soon as a solution thereof is diluted to produce a solids content between 10% and 40%. I

9. Process of claim 1 in which the ratio ofresin to colloid is in the range of 1:4 and 15:1.

7 10. Process of claim 1 'iniwhich the ratio of resin to colloid is in the range-of 1:4 and 4:1.

11. Process of claim 1 in which the ratio of resin to colloid is in the-range of 1:2 and 2:1.

12,- Process of claim 1 in which the treated material is a fabric and the latter, after impregnation is passed between heated embossing or glazing rollers.

13. A composition for deposition of hydrophilic colloids in fibrous material by impregnation which comprises an aqueous stable colloidal suspension containing the hydrophilic colloid, a urea condensation product of low water tolerance, and a catalyst for the latter, the aqueous colloidal suspension containing up to 30% of the condensation product, and the composition upon dilution with water depositing the condensation product in intimate association with the colloid.

14. Composition of claim 13 in which the hydrophilic colloid is a substance selected from the group consisting of starch, gelatine, carboxymethyl cellulose and polyvinyl alcohol.

15. Composition of claim 13 in which the mol ratio of urea to formaldehyde in the condensation product is between 1:15 and 1:2.

16. Composition of claim 13 in which the mol ratio of urea to formaldehyde in the condensation product is between 1:1.6 and 1:1.8.

17. Composition of claim 13 in which the ratio of resin to colloid is in the range of 1:4 to 15: 1.

18. Composition of claim 13 in which the ratio of resin to colloid is in the range of 1:4 to 4:1.

19. Composition of claim 13 in which the ratio of resin to colloid is in the range of 1:4 to 2:1.

20. A textile material carrying a substantially waterfast durable finish of the solids content of the composition of claim 13.

21. Textile material of claim 20 in which the hydrophilic colloid is a substance selected from the group consisting of starch, gelatine, carboxymethyl cellulose and polyvinyl alcohol.

22. Textile material of claim 20 in which the mol ratio of urea to formaldehyde in the condensation product is between 1:15 and 1:2.

23. Textile material of claim 20 in which the ratio of resin to colloid is in the range of 1:1.6 and 1:1.8.

24. Textile material of claim 20 in which the ratio of resin to colloid is in the range of 1:4 to 15:1.

25. Textile material of claim 20 in which the ratio of resin to colloid is in the range of 1:4 to 4:1.

26. Textile material of claim 20 in which the ratio of resin to colloid is in the range of 1:4 to 2:1.

References Cited in the file of this patent UNITED STATES PATENTS 2,121,205 Lippert et al June 21, 1938 2,255,901 Schroy Sept. 16, 1941 2,400,820 Glarum et al. May 21, 1946 2,586,188 Van Wirt et a1 Feb. 19, 1952 

1. PROCESS OF DEPOSITION OF HYDROPHILIC COLLOIDS IN FIBROUS MATERIALS, IN WHICH PROCESS A FIBROUS MATERIAL IS IMPREGNATED WITH AN AQUEOUS PREPARATION CONTAINING THE COLLOID, A UREA-FORMALDEHYDE CONDENSATION PRODUCT, AND A CATALYST FOR THE LATTER, A UREA-FORMALDEHYDE CONDENSATION PRODUCT OF LOW WATER TOLERANCE BEING USED IN THE MAKING UP OF THE AQUEOUS PREPARATION, AN AQUEOUS SOLUTION OF SAID CONDENSATION PRODUCT BEING DILUTED WITH WATER IN THE PRESENCE OF THE COLLOID SO THAT IT IS THROWN OUT OF SOLUTION INTO INTIMATE ASSOCIATION WITH THE COLLOID, THE AQUEOUS PREPARATION CONTAINING UP TO 30% OF THE CONDENSATION PRODUCT. 